Epidemiological characteristics of Leptospira spp. infection in bovine herds in Mato Grosso do Sul, Brazil / Caracterização soroepidemiológica da infecção por Leptospira spp. em rebanhos bovinos de corte do estado de Mato Grosso do Sul, Brasil

The epidemiological characteristics of bovine leptospirosis in animals and herds in Mato Grosso do Sul were investigated to determine parameters such as disease frequency and the serovars reactant in beef cattle herds. A total of 4,629 beef cattle herds were examined against 33 Leptospira spp. serovars. The serum samples were submitted to the microscopic agglutination test (MAT) for the serological diagnosis of leptospirosis. The MAT results showed that 3,814 (82.39%) of the 4,629 animals evaluated were seropositive for the bacterium, with serological reactions mainly to serogroup Sejroe, serovar Wolffi (36.49%). The observed high frequency of reactive animals demonstrates the relevance of the infection. Therefore, general and specific measures should be implemented to contain and/or prevent infection of the animals in the studied region.(AU)

Foi realizado um inquérito epidemiológico da leptospirose em bovinos de rebanhos de corte do estado de Mato Grosso do Sul, de modo a determinar a frequência e as sorovariedades reagentes. Para isso, foram examinados 4.629 bovinos de corte, com uma coleção de 33 sorovariedades de Leptospira, por meio da prova de Soroaglutinação Microscópica (MAT). Dos 4.629 animais examinados, 3.814 (82,39%) foram reagentes com reações predominates para o sorogrupo Sejroe, sorovar Wolffi (36,49%). Assim, a alta frequência de animais reagentes encontrada justifica a implantação de medidas gerais e específicas para conter e/ou prevenir a infecção nos animais dessa região.(AU)

Spatial distribution of serologically reactive sheep to Leptospira spp. in the northeast region of Brazil

Considering the importance of leptospirosis in sheep farming and public health and the significance of identifying which serogroups circulate in sheep within each region, the objective of this study was to determine the seroprevalence and spatial distribution of the most frequent serogroups causing infection by Leptospira sp. in ovine herds in the Northeast region of Brazil. Blood samples were collected from 4197 sheep from 229 herds in 7 Northeastern States. Sera were analyzed via microscopic agglutination test (MAT). The frequency of seroreactive sheep for Leptospira sp. was 14.06%. The states of Alagoas, Ceará, Paraíba, Piauí, Rio Grande do Norte, and Sergipe, located in the Caatinga biome, had the highest frequencies of serologically reactive sheep, and Maranhão, in the Cerrado biome, had the lowest frequency. The most frequent serogroups were Autumnalis (19.49%), Australis (15.76%) and Serjoe (14.41%). In the states of Ceará, Paraíba, Rio Grande do Norte, and Sergipe, 100% of their municipalities had at least one seroreactive animal. The highest frequencies of seropositive animals were found in the municipalities of União (50%), Passagem (49.06%), Canindé (48.89%), Igaci (28.95%), Gararu (31.2%), Pirapemas (17.5%), and Angicos (16%) located in the states of Piauí, Paraíba, Ceará, Alagoas, Sergipe, Maranhão and Rio Grande do Norte, respectively. The animal-level prevalence (14.06%) obtained in the present study is significant, especially considering the rustic nature of the species and the adverse conditions of the region for the infectious agent. In semi-arid conditions, it has been suggested that perhaps sheep do not seroconvert detectable titers on MAT with a cut-off point of 1:100. It is important to highlight that the ovine population in the Northeast region of Brazil is composed of mixed animals, which have been considered more resistant to infection by Leptospira spp. Also, environmental factors hostile to the survival of the infectious agent in the studied region should be taken into consideration, since they may have influenced the seropositive animal-level prevalence. A noteworthy variation was observed in agglutinin titers, which ranged from 100 to 1,600, where 80.2% of the positive samples had titers ≤ 200. It is important to highlight that more elevated titers (≥ 400) were obtained in all seven states, which may suggest an acute infection caused by a non-adapted serovar, indicating that preventive and control measures focused on possible infection sources for sheep should be adopted. Although some states showed the same serogroups as the most frequent, a variety of serogroups was observed in municipalities, which may indicate different sources of infection, whether interspecies, intraspecies, or via alternative routes of transmission in semi-arid conditions, such as venereal. This indicates that even though sheep are more resistant to infection, they become exposed due to the environment or management conditions. As such, identification, isolation, and treatment of the affected animals are alternative measures recommended for prevention and control of leptospirosis in sheep in the semi-arid region. It is evident that despite the lack of rain observed in the last decade in the Northeast region of Brazil, which prevented the formation of favorable environments for the presence of Leptospira, the infectious agent remains among the sheep, as well as other production and wild animals in the region. Some factors may be contributing to this scenario, such as the fact that sheep farming in the region is = characterized mainly by subsistence systems, where veterinary assistance and adequate sanitary management are absent, thus increasing the possibility of contact with Leptospira. (AU)

Frequency of antibodies and risk factors associated with Toxoplasma gondii infection in backyard pig production in the city of Mossoró, state of Rio Grande do Norte, Brazil / Frequência de anticorpos e fatores de risco associados à infecção por Toxoplasma gondii em criações de suínos em Mossoró, Rio Grande do Norte

Abstract Toxoplasmosis is an important zoonosis for pregnant women and immunosuppressed people. The pig population also becomes infected by this pathogen, and undercooked or raw meat is an important source of infection for humans. The aims of the present study were to evaluate the rate of exposure of pigs to T. gondii in the municipality of Mossoró, Rio Grande do Norte and seek to identify associations with possible risk factors. Blood samples were collected from 412 pigs and were analyzed using the immunofluorescence assay. Among these 412 serum samples, 40.7% were seropositive for T. gondii. The IgG antibody titers were 64 (56 specimens), 128 (32), 256 (37), 512 (23), 1024 (14), 2048 (5) and 4046 (1). Seropositivity for T. gondii was found to be related (p-value < 0.05) to the following factors: female gender, semi-confined rearing system, use of well water, dewormed animals, presence of cats, goats, sheep, mice and vultures on the farm and carcasses left on the ground. In contrast, seropositivity was not related (p-value < 0.05) to the age of the pigs, type of facility or feeding with human food remains. Preventive measures need to be adopted on the farms studied here, with the aim of decreasing the animals' intake of sporulated oocysts.

Resumo A toxoplasmose é uma importante zoonose para mulheres grávidas e pessoas imunossuprimidas. Os suínos também são infectados por este patógeno; e a carne crua ou malcozida é uma importante fonte de infecção para o ser humano. O objetivo do presente trabalho foi avaliar a taxa de exposição suína à T. gondii no município de Mossoró, Rio Grande do Norte e identificar associações com possíveis fatores de risco. Amostras de sangue foram coletadas em tubos sem anticoagulante e o soro foi separado de 412 porcos e analisadas pelo ensaio de imunofluorescência. Dentre as 412 amostras de soro, 40,7% foram positivas para T. gondii. Os títulos para o anticorpo IgG foram 64 (56 amostras); 128 (32); 256 (37); 512 (23); 1024 (14); 2048 (5) e 4046 (1). A soropotividade para T. gondii foi relacionada (p-valor < 0,05) aos seguintes fatores: gênero feminino, sistema de criação de semi-confinamento, uso de água de poço, animais vermifugados, presença de gatos, cabras, ovelhas, ratos e urubus na fazenda e carcaças deixadas à céu aberto. Em contrapartida, a soropositividade não foi relacionada (p-valor < 0,05) à idade dos suínos, tipo de instalações ou alimentação com restos de comida humana. As adoções de medidas preventivas são necessárias na propriedade estudada, objetivando diminuir a ingestão de oocistos esporulados pelos animais.

Evaluation of dot-blot test for serological diagnosis of bovine brucellosis

Abstract The objective of this study was to standardize and validate the dot-blot test for the serological diagnosis of bovine brucellosis, compare the results with those found in the 2-mercaptoethanol (2-ME) and complement fixation test (CF), and estimate the relative sensitivity and specificity of the dot-blot compared to these tests. Fifty bovine blood serum samples were used for the test standardization, and 1315 samples were used for evaluation and comparison between the tests; the results were compared using the Kappa indicator. At the end of standardization, it was established as optimal for the antigen obtained from Brucella abortus B19 after passing through a microorganism rupture process, the blood serum samples diluted at 1:100, and the conjugate at 1:30,000. The comparison of the dot-blot results with 2-ME showed Kappa index of 0.9939, sensitivity of 99.48%, and specificity 99.91%, with CF, Kappa index of 0.8226, sensitivity 100% and specificity 95.32%. Using the combination of the test results 2-ME and CF to establish the true condition of the animal, the dot-blot showed relative sensitivity of 100%, and relative specificity of 99.91%. The evaluated test proved to be effective and reliable, besides being easy to handle and interpret the results.

Perfil da ocorrência de raiva animal em diferentes espécies no Estado de Mato Grosso, Brasil, de 2002 a 2011 / Profile of the occurrence of animal rabies in different species in the State of Mato Grosso, Brazil, of 2002 the 2011

A raiva é uma zoonose viral, que acomete o Sistema Nervoso Central, de evolução aguda e quase sempre fatal. Através das notificações enviadas à SES-MT (Secretaria de Estado de Saúde de Mato Grosso), foi realizado um mapeamento dos casos positivos de raiva nas diferentes espécies, que ocorreram no período de 2002 a 2011 no Estado de Mato Grosso. Foram diagnosticados 915 casos de raiva no estado durante esse período. Animais de diferentes espécies foram acometidos pela enfermidade. A espécie bovina foi notadamente a mais notificada com 80,00% (736) dos casos, seguida pela canina com 12,56% (115), a equina 5,57% (51), a quiróptera 0,65% (6), felina, suína, ovina e muar com 0,21%, (2, 2, 2, 3) casos, e as espécies caprina e primata com 0,1% (1) cada uma. No entanto, houve uma redução significativa no número de casos caninos no decorrer dos anos, com ausência de notificações a partir do ano de 2008. Nesse sentido, foi possível observar que diferentes espécies foram acometidas, evidenciando a circulação viral no Estado de Mato Grosso.

High occurrence of Mycoplasma suis infection in swine herds from non-technified farms in Mossoró, state of Rio Grande do Norte, Northeastern Brazil / Alta ocorrência de infecção por Mycoplasma suis em suínos de criações não tecnificadas de Mossoró, estado do Rio Grande do Norte, Nordeste brasileiro

Abstract Mycoplasma suis, the etiological agent of swine hemoplasmosis, has been neglected in swine herds around the world. Swine hemoplasmosis is frequently associated with hemolytic anemia, disgalacty, infertility and immunosuppression, and it results in significant economic losses. This study investigates the occurrence of M. suis in non-technified swine herds in the northeastern region of Brazil using quantitative PCR (qPCR) based on the 16S rRNA gene. Between March and August 2013, blood samples from 147 swine were collected during slaughter in the city of Mossoró, state of Rio Grande do Norte, northeastern Brazil. One hundred and twelve samples (76.19%) were positive for M. suis by qPCR assays. The range of Cqs and quantification (copies of a M. suis-16S rRNA gene fragment/µL) was 20.86–37.89 and 1.64×101–6.64×107, respectively. One can conclude that M. suis infection have high occurrence (76,19%) in non-technified swine-rearing systems in Mossoró in the state of Rio Grande do Norte, Brazil.

Resumo Mycoplasma suis, agente etiológico da hemoplasmose suína, tem sido negligenciado nas criações de suínos ao redor do mundo. A hemoplasmose suína é frequentemente associada à anemia hemolítica, disgalactia, infertilidade e imunossupressão, acarretando em perdas econômicas. O objetivo do presente trabalho foi investigar, por meio da PCR quantitativa (qPCR) baseada no gene rRNA 16S, a ocorrência de M. suis em amostras de sangue de suínos de criações não tecnificadas na cidade de Mossoró, Estado do Rio Grande do Norte. Entre março a agosto de 2013, foram colhidas amostras de sangue de 147 suínos de criações não tecnificadas da referida região. Cento e doze amostras (76,19%) amostras mostraram-se positivas na qPCR para M. suis. A média dos Cqs e da quantificação (número de cópias do gene 16S rRNA de M. suis por microlitro) foi de 20,86 – 37,89 e 1,64 x 101 a 6,64 x 107, respectivamente. Conclui-se que a infecção por M. suis apresenta alta ocorrência (76,19%) em criações de suínos não tecnificadas na cidade de Mossoró, estado do Rio Grande do Norte.

A cross-sectional study to estimate the frequency of anti-bovine viral diarrhea virus-1 antibodies in domestic pigs of Mossoró region in the state of Rio Grande do Norte, Brazil / Estudo transversal para estimar a frequência de anticorpos anti-vírus da diarreia viral bovina-1 em suínos domésticos da região de Mossoró, no estado do Rio Grande do Norte, Brasil

ABSTRACT: This study investigated the occurrence of antibodies for BVDV-1 in swine herds located in the region of Mossoró city of the state of Rio Grande do Norte, Brazil. A sample size of 412 animals was estimated assuming unknown prevalence (set at 50%). Virus neutralization assay was used to the detect the presence of antibodies for BVDV-1 and the results found were analysed using multivariable logistic regression model. The obtained prevalence was 4% at animal level and 45% at the animal and herd level. The titers were highly variable between animals and within farms. The multivariable logistic regression analysis showed an association between being housed outside and exposure to BVDV-1 (OR=0.24, 95% CI:0.06, 0.96, P=0.04). Highly correlated data and low prevalence of antibodies at the animal level resulted in insufficient power to detect significant differences with other selected risk factors. In conclusion, the prevalence is within the range reported for other countries.

RESUMO: Este estudo investigou a ocorrência de anticorpos contra o BVDV-1 em rebanhos suínos localizados na região da cidade de Mossoró do Estado do Rio Grande do Norte, Brasil. Um tamanho de amostra de 412 animais foi estimado assumindo uma prevalência desconhecida (fixada em 50%). O teste de virusneutralização foi utilizado para detectar a presença de anticorpos ao BVDV-1 e os resultados obtidos foram analisados usando o modelo de regressão logística multivariada. A prevalência obtida foi de 4% em nível animal e de 45% dos rebanhos. Os títulos foram muito variáveis entre os animais e dentro de fazendas. A análise de regressão logística multivariada apontou associação entre animais criados soltos e a exposição ao BVDV-1 (OR=0,24; 95% IC: 0,06; 0,96; P=0.04). A alta correlação entre os dados junto com a baixa prevalência de anticorpos a nível animal pode ter sido insuficiente para que as diferenças reais fossem detectadas. Em conclusão, a prevalência está dentro do intervalo referido em outros países.